Ext.define('AM.model.User', {
         extend: 'Ext.data.Model',
         fields: [
         {name: 'id', type:'int',mapping : 'id'},
         {name: 'name', type:'string',mapping : 'name'},
         {name: 'age', type:'int',mapping : 'age'},
         {name: 'marks',type:'float', mapping : 'marks'}
         ]
         ,proxy: {
                 type: 'rest',
                 url : 'http://localhost:3000/users'
             }
      });